In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 35, No. 17 ( 2020-09-14), p. 2300-2310
Abstract:
Calcium–magnesium–alumino-silicate (CMAS) particulates enter the aero-engine in a sandy environment, melt and infiltrate into 7 wt% yttria-stabilized zirconia (7YSZ) thermal barrier coatings (TBCs), reducing their lifetime. This leads to chemical degradation in 7YSZ accompanied by tetragonal to monoclinic phase transformation upon cooling. In this work, electron-beam physical vapor deposition coatings were infiltrated with a synthetic CMAS. Synchrotron X-ray diffraction measurements show that CMAS infiltration at 1250 °C has about 43% higher monoclinic phase volume fraction (PVF) at the coating surface compared to 1225 °C and remains consistently higher throughout the coating depth. Additionally, the increase in annealing time from 1 to 10 h results in a 31% higher monoclinic phase at the surface. Scanning electron microscopy revealed the presence of globular monoclinic phases corresponding spatially with the above findings. These results resolve the impact of time and temperature on CMAS infiltration kinetics which is important for mitigation.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/jmr.2020.212
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2020
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8
